Phase equilibria in the ternary reciprocal system Li,Rb‖F,CrO4

The ternary reciprocal system of fluorides and chromates of lithium and rubidium was studied for the first time. The stable pair of salts LiF and Rb₂CrO₄ and also binary compounds on the bordering sides partition the system into five simplexes. Studying a number of polythermal sections allowed us to determine the melting points and compositions of two peritectics and three eutectics. The crystallization fields of phases in the system were demarcated, and phase equilibria were described.     

Chemical interaction in the quaternary mutual systems Li,K‖F,Cl,MoO4 and Li,K‖F(Cl),VO3,MoO4

The Li,K‖Cl,VO₃,MoO₄ system was partitioned into simplexes using graph theory, and the tree of phases for this system was constructed. The equations of the main reactions describing the chemical interaction in the quaternary mutual systems Li,K‖F,Cl,VO₃(MoO₄) and Li,K‖F(Cl),VO₃,MoO₄ were derived using the conversion patterns of partitioning elements. Based on the reaction equations and the data on the boundary elements, the prediction of phases crystallizing in the studied systems was made and confirmed by X-ray powder diffraction analysis.     

Phase complex of the Li,K,Ba‖F,Br quaternary reciprocal system

The partition of the Li,K,Ba??F,Br quaternary reciprocal system into simplexes was performed and confirmed by X-ray powder diffraction. Internal partitioning elements, LiF-2KBr · BaBr₂ and KBr-LiF · BaF₂, were identified; the tree of phases forms two cycles. Simplexes involving phase separation were determined. The stable partitioning triangles LiF-KBr-BaBr₂ and LiF-KBr-BaF₂ · BaBr₂ were experimentally studied by differential thermal and X-ray powder diffraction analyses. The T-x diagrams of explored sections and the liquidi of the systems were constructed. Phase separation regions within the systems under investigations were delimited. The characteristics of alloys corresponding to invariant compositions were determined.     

Partition of the Li,K‖F,Cl,Br quaternary reciprocal system into simplexes and investigation of components of the LiF-KCl-KBr stable triangle

A quaternary reciprocal system of fluorides, chlorides, and bromides of lithium and potassium was partitioned into simplexes by a geometric method and by a graph method. Phase transformations and chemical reactions in the boundary ternary reciprocal systems were described. A conversion line was experimentally studied, and information on crystallizing phases within the composition prism of the Li,K‖F,Cl,Br system was obtained and confirmed by X-ray powder diffraction data. An immiscibility region in the LiF-KCl-KBr stable triangle was outlined.     

Stable tetrahedron LiF-KCl-KBr-K2MoO4 of the quinary reciprocal system Li,K‖F,Cl,Br,MoO4

The stable tetrahedron LiF-KCl-KBr-K₂MoO₄ of the quinary reciprocal system Li,K‖F,Cl,Br,MoO₄ was studied by differential thermal analysis, and phase equilibria were determined.     

Investigation of the United stable tetrahedron LiF-KBr-K2MoO4-KF of the quaternary reciprocal system Li,K‖F,Br,MoO4

The united stable tetrahedron LiF-KBr-K₂MoO₄-KF of the quaternary reciprocal system Li,K‖F,Br,MoO₄ was studied by differential thermal analysis. The melting points and ternary eutectic and peritectic compositions in the secant triangle LiF-KBr-K₃FMoO₄ were identified. The melting points of the samples corresponding to the quaternary invariant equilibrium points (eutectic and peritectic points) and their compositions in the stable tetrahedron LiF-KBr-K₃FMoO₄-KF were determined. The volumes of crystallizing phases in the united stable tetrahedron were determined; the phase equilibria at invariant points were described.     

Phase complex of the Na,K‖Br,MoO4 system

The Na,K‖Br,MoO₄ system was studied by differential thermal analysis and X-ray powder diffraction. It was established that the liquidus surface consists of the crystallization fields of the initial components and the incongruently melting compound NaKMoO₄. The coordinates of three nonvariant points were determined, which represent one eutectic, E ^Δ, and two peritectics, P ₁ ^Δ , and P ₂ ^Δ , with the melting points 472, 512, and 538°C, respectively, and the specific enthalpies of melting Δ_melt H = 177, 230, and 184 kJ/kg, respectively.     

Study of series of the M1,M2‖F,Cl,Br quaternary reciprocal systems (M1 and M2 are group 1 s-block elements)

Quaternary reciprocal systems of alkali metal fluorides, chlorides, and bromides were partitioned into simplexes by a geometric method and a graph method. Phase transformations and chemical reactions in the bordering ternary reciprocal systems were described. Conversion lines were experimentally studied, and information on crystallizing phases within the composition prisms of the M₁,M₂‖F,Cl,Br systems (M₁ and M₂ are group 1 s-block elements) was obtained.     

Differentiation of the Na,K,Ca,Ba‖F,WO4 multicomponent system and phase equilibria in its stable secant complex NaF-K2WO4-CaF2-BaF2

The Na,K,Ca,Ba‖F,WO₄ quinary mutual system was differentiated based on graph theory with consideration of identified internal secant elements using a program complex. For the first time, by a combination of physicochemical analysis methods (differential thermal, visual polythermal, X-ray diffraction and projection-thermal-analytical), the NaF-K₂WO₄-CaF₂-BaF₂ quaternary system was studied, which is a stable secant complex of the quinary mutual system. The coordinates of invariant points were determined.     

Phase equilibria and structures of phases in the chitosan—polyvinyl alcohol systems

Russian Chemical Bulletin - Phase equilibria in the mixtures of polyvinyl alcohol (PVA) and chitosan were revealed. Structures of the phases were identified. The temperature and concentration...     

Interaction of salts in ionic melts of the ternary reciprocal systems Na,K‖BO2,MoO4 and Na,K‖BO2,WO4

The phase diagrams of the ternary reciprocal systems Na,K‖BO₂,MoO₄ and Na,K‖BO₂,WO₄ were studied for the first time by a calculation-experimental method and differential thermal analysis. The coordinates were determined for binary eutectics of the diagonal stable sections NaBO₂-K₂MoO₄(K₂WO₄) and the ternary invariant points e(55 mol % NaBO₂, 45 mol % K₂MoO₄, 740°C), e(55 mol % NaBO₂, 45 mol % K₂WO₄, 730°C), E(4.5 mol % NaBO₂, 78 mol % Na₂MoO₄, 17.5 mol % K₂MoO₄, 652°C), E(4.5 mol % NaBO₂, 78 mol % Na₂WO₄, 17.5 mol % K₂WO₄, 643°C), P₂(5 mol % NaBO₂, 56 mol % Na₂MoO₄, 39 mol % K₂MoO₄, 673°C), P₂(5 mol % NaBO₂, 56 mol % Na₂WO₄, 39 mol % K₂WO₄, 671°C). Binary solid solutions based on sodium and potassium metaborates were shown to be stable. Analytical models of phase equilibrium states of the ternary reciprocal systems Na,K‖BO₂,MoO₄(WO₄) were obtained, which enable one to calculate melting (crystallization) points and construct isotherms at any given composition. The specific heats of melting of samples of invariant compositions were found by quantitative differential thermal analysis.     

Phase equilibria in the Na,Ca‖SO4,CO3,F-H2O at 0°C

Phase equilibria in the Na,Ca‖SO₄,CO₃,F-H₂O system at 0°C were studied using the translation method. Seven invariant points, 18 monovariant curves, and 17 divariant fields were found to exist. A looped phase diagram (phase complex) of the title system was constructed.     

Na,Rb‖F,Br three-component reciprocal system and analysis of the Na,M‖F,Br (M = K,Rb, and Cs) series

Solid-phase reactions were studied by differential thermal analysis and X-ray powder diffraction in a sample whose composition corresponds to the complete conversion point K of the Na,Rb‖F,Br three-component reciprocal system. A stable diagonal and a metastable diagonal were studied, and the parameters of two ternary eutectics were determined.     

Li,K∥F,NO3 and Li,K∥Cl,NO3 three-component reciprocal systems

Phase equilibria in Li,K∥F,NO₃ and Li,K∥Cl,NO₃ three-component reciprocal systems were studied by differential scanning calorimetry (DSC). Eutectic compositions (mol %) in the Li,K∥F,NO₃ system were determined to be as follows: 5.0 LiF, 10.0 KF, and 85.0 KNO₃ with T _m = 281°C and 48.5 KNO₃, 44.0 LiNO₃, and 7.5 LiF with T _m = 105°C. Eutectic compositions (mol %) in the Li,K∥Cl,NO₃ system were determined to be as follows: 10.0 LiCl, 32.1 KCl, and 57.9 LiNO₃ with T _m = 147°C and 44.5 KNO₃, 45.0 LiNO₃, and 10.5 KCl with T _m = 97°C.     

Phase equilibria in the Na,K,Mg,Ca‖SO4,Cl-H2O system at 50°C in the halite crystallization field

Phase equilibria of the Na,K,Mg,Ca‖SO₄,Cl-H₂O system at 50°C in the halite (NaCl) crystallization field were studied using the translation method. Halite, which is an equilibrium phase of the title system at 50°C, was found to be involved in 25 invariant points, 59 monovariant curves, and 43 divariant fields. A fragment of the equilibrium phase diagram of the title system in the halite crystallization field was constructed.     

Phase equilibria in the Na,K,Mg,Ca‖SO4,Cl-H2O system at 50°C in the astrakhanite crystallization region

Phase equilibria of the Na,K,Mg,Ca‖SO₄,Cl-H₂O system at 50°C in the astrakhanite (Na₂SO₄ · MgSO₄ · 4H₂O) crystallization region were studied using the translation method. Astrakhanite was found to be involved, as an equilibrium phase of the title system, in 35 divariant fields, 39 monovariant curves, and 22 invariant points. The data gained were used to construct a fragment of a schematic equilibrium phase diagram of the title system in the astrakhanite crystallization region.     

Li,K‖Cl,MoO4 ternary mutual system

Phase equilibria in the Li,K‖Cl,MoO₄ ternary mutual system were studied by differential thermal analysis (DTA). The characteristics of the following three ternary eutectics were determined: E ₁: 348°C, 41 mol % KCl, 7.75 mol % Li₂MoO₄, and 51.25 mol % LiCl; E ₂: 475°C, 44 mol % KCl, 17.25 mol % Li₂MoO₄, and 38.75 mol % LiCl; and E ₂: 477°C, 35 mol % KCl, 47 mol % Li₂MoO₄, and 18 mol % LiCl.     

Phase equilibria in the Sn–As–Ge and Sn–As–P systems

T–x diagrams of polythermal GeAs–SnAs, GeAs–Sn₄As₃ sections of the Sn–As–Ge system and Sn₄P₃–Sn₄As₃ section of the Sn–As–P system were constructed using the results of X-ray powder diffraction and differential thermal analyses. It was found that the section GeAs–Sn₄As₃ is not quasi-binary due to realization of four-phase peritectic transformation L + SnAs ? GeAs + Sn₄As₃ at the temperature of 834 K. The quasi-binary section GeAs–SnAs represents a phase diagram of the eutectic type with the following coordinates of eutectic reaction: temperature of the eutectic point is 840 K, and composition is 20 mol% GeAs. In the Sn–As–P system, the existence of the solid-solution range indicated as (Sn₄As₃) _x (Sn₄P₃)_1?x  was defined. The polythermal section Sn₄P₃–Sn₄As₃ is not quasi-binary due to the fact that in the composition range with a high content of tin arsenide discussed section intersects the peritectic part of the three-phase volume (L + SnAs + α) of the ternary diagram.     

Li, K‖Br, VO3 ternary mutual system

Phase equilibria in the Li, K‖Br, VO₃ ternary mutual system were studied by differential thermal analysis. The composition square of the ternary mutual system is divided into two phase triangles, LiVO₃-KBr-KVO₃ and LiBr-LiVO₃-KBr. The ternary eutectics E ₁ at 331°C and E ₂ at 330°C have the compositions 40.0 mol % LiVO₃, 6.0 mol % KBr, 54.0 mol % KVO₃ and 58.0 mol % LiBr, 3.2 mol % LiVO₃, 38.8 mol % KBr, respectively. The fields of phases crystallizing in the system were delimited.